On 12 March 2011 22:19, Neil Chaudhuri <[email protected]> wrote:
> So I pretty much ripped this off verbatim from the Gradle Cookbook:
>
>
>
> task aggregateJavadoc(dependsOn: clean, type: Javadoc) {
>
> source subprojects.collect { project ->
>
> project.sourceSets.main.allJava
>
> }
>
> destinationDir = file("${buildDir.absolutePath}/javadoc")
>
> classpath = files(subprojects.collect { project ->
>
> project.sourceSets.main.compileClasspath
>
> })
>
> }
>
>
>
> When I run this, everything works as expected.
>
>
>
> But when I add << and run the following I get an error:
>
>
>
> task aggregateJavadoc(dependsOn: clean, type: Javadoc) << {
>
> source subprojects.collect { project ->
>
> project.sourceSets.main.allJava
>
> }
>
> destinationDir = file("${buildDir.absolutePath}/javadoc")
>
> classpath = files(subprojects.collect { project ->
>
> project.sourceSets.main.compileClasspath
>
> })
>
> }
>
>
>
> The error is
>
>
>
> Execution failed for task ':aggregateJavadoc'.
>
> Cause: Error validating task ':aggregateJavadoc': No value has been
> specified for property 'destinationDir'.
>
>
>
> Again, the task is precisely written as the other but with the << added
> only.
>
>
>
> I’ve read the docs pretty carefully on the lifecycle, and I am not able to
> figure out what the difference is between these two executions. I can see
> how something can fail in the configuration phase because not everything has
> been configured, but I have trouble understanding how anything can fail in
> the execution phase once everything is in place.
>
>
>
> Any insight into the difference between these two tasks is appreciated.
>
'<<' is an abbreviation for 'doLast'. The last case is equivalent to the
following code:
task aggregateJavadoc(dependsOn: clean, type: Javadoc) {
// Oops, no destinationDir specified here...
doLast {
source subprojects.collect { project ->
project.sourceSets.main.allJava
}
destinationDir = file("${buildDir.absolutePath}/javadoc")
classpath = files(subprojects.collect { project ->
project.sourceSets.main.compileClasspath
})
}
}
The destinationDir assignment is in the wrong place. The Javadoc task needs
a destination directory to do its work. When you specify the destination
directory in a doLast closure, you are 'too late'.
cheers,
--L
